Far in the future, America still exists. The U.S.A comprises of 60 Earthern states and some 55 other worlds, totalling a union of 115 states, ruled by central government from Washington.
When aliens attacked European colonies in space, they banded together and formed G.A.I.A, an united European alliance designed to rally a great space fleet. The U.S.A immedietly formed there own version of a similar nature, Am-Space.